Collaborative Research: Photochemical Silicon Aerosols: Establishing Atmospheric Sources and Significance

这项研究的重点是提高对挥发性甲基硅氧烷（VMS）在大气中的化学和物理转化的理解。挥发性甲基硅氧烷（VMS）是许多个人护理产品（如润肤剂和乳液）中使用的高产化学品。这项研究的结果，预计将导致更好地评估的命运和运输问题的重要了解的环境和健康的后果，越来越多的使用VMS.本项目的目标是评估化学形态和丰富的氧化VMS在实验室和周围大气气溶胶。这项研究预计将证实存在由环境有机硅化合物形成的颗粒，建立在城市和远程氧化条件下近环境条件下的气溶胶产量，确定这类二次有机气溶胶的最佳气溶胶示踪剂化合物，并将这一努力的结果纳入一个国家，科学的光化学网格模型，这将使预测VMS的命运后，氧化的规模从城市的空气流域到大陆。这项研究包括实验室研究，在爱荷华州大学使用氧化流动反应器（OFR）和实验在科罗拉多大学的环境室探测VMS的氧化化学。VMS及其气相和凝相氧化产物的室外环境采样将在为期四周的夏季部署期间在纽约市大都市区进行。从这项研究中获得的科学见解将被纳入社区多尺度空气质量（CMAQ）建模系统，这将导致更好地预测个人护理产品的气溶胶形成。该项目由NSF大气化学计划和刺激竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This research is focused on improving the understanding of the chemical and physical transformations of volatile methyl siloxanes (VMS) in the atmosphere. Volatile methyl siloxanes (VMS) are high production chemicals used in many personal care products such as deodorants and lotions. The results of this research are expected to lead to a better assessment of the fate and transport issues important for understanding the environmental and health consequences of the increasing use of VMS.The objective of this project is to assess the chemical speciation and abundance of oxidized VMS in the laboratory and in ambient atmospheric aerosols. This research is expected to confirm the presence of particles formed from ambient organosilicon compounds, establish aerosol yields at near-ambient conditions under urban and remote oxidation conditions, determine the best aerosol tracer compounds for this class of secondary organic aerosols, and integrate the results of this effort into a state-of-science photochemical grid model that will enable the prediction of the fate of VMS upon oxidation at scales ranging from urban airshed to continental.This research includes laboratory studies at the University of Iowa using an oxidative flow reactor (OFR) and experiments in the University of Colorado environmental chambers to probe the oxidation chemistry of VMS. Outdoor ambient sampling for VMS and its gas- and condensed-phase oxidation products will be conducted during a four-week summertime deployment in the New York City metropolitan area. The scientific insights gained from this research will be incorporated into the Community Multiscale Air Quality (CMAQ) modeling system that will lead to better predictions of aerosol formation from personal care products.This project is jointly funded by the NSF Atmospheric Chemistry Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.